5x-7
If the first side is just x, then the second side must be 2x-5, or 5 less than twice the first. If this is the second side, then the third must be 2x-2, because the third side "measures 3 more than the second side."
The perimeter is 5x-7 = (x) + (2x-5) + (2x-2).
Do you remember how to find the area of a circle ?
Big Fat Hint: The area of a circle is (pi) x (its radius)² .
Can you find the area of the big circle ... the one with radius = 18 m ?
Do that. The whole big circle, just as if there was nothing inside it, and
no shaded region.
I'll wait.
Now, can you find the area of the small circle ... the one with radius = 12 m ?
Do that.
I'll wait.
The area of the shaded region is just
(the area of the big circle) minus (the area of the small circle) !
I got 180 pi or roughly 565.2 m². I could be wrong. You should check it.
The answer is the last one
15 + (3/2)t ≤ 12
400=12.50x+50
400-50=12.50x
350=12.50x
350÷12.50=x
28=x
he would have to sell 28 news paper subscriptions